Difference between revisions of "Jetty/Howto/Configure Virtual Hosts"

(New page: {{Jetty Howto | introduction = A virtual host is an alternative name, registered in DNS, for an IP address. A single IP address may have many such alternative names. Multi-homed hosts, t...)

Introduction

A virtual host is an alternative name, registered in DNS, for an IP address. A single IP address may have many such alternative names.

Multi-homed hosts, that is machines with more than one network interface, may have a different name for each IP address. This is also refered to as "virtual hosting".

Essentially, "virtual hosting" concerns the resolution of a DNS registered name to an IP address - many names may resolve to the same IP address, and 1 or more IP addresses may reside on the same physical machine.

Jetty users often want to configure their web applications taking into account these different virtual hosts. Frequently, a machine with a single IP address will have different DNS resolvable names associated with it, and a webapp deployed on it must be reachable from all of the alternative names.

Other possibilities are to serve different web applications from different virtual hosts.

Let's examine these possibilities.

Configuration of virtual hosts

When configuring a web application, you can supply a list of IP addresses and names at which the web application will be reachable. Suppose we have a machine with these IP addresses and DNS resolvable names:

333.444.555.666

127.0.0.1

www.blah.com

www.blah.net

www.blah.org

Suppose we have a webapp, xxx.war that we want to be served from all of the above names and addresses. Then we would configure the webapp like so:

Configuring different webapps for different virtual hosts, but at the same context path

In our example above, we have made webapp zzz.war avilable not only at a certain set of virtual hosts, but also at the context path /zzz, whilst our other webapp is available at both a different set of virtual hosts, and at a different context path. What happens if we want them at the same context path, but still at different sets of virtual hosts?

Very simply, we just supply the same context path for each webapp, leaving the disjoint set of virtual host definitions as before: